Move Over Medical Illness Model - A New (or Rather Old) Model is Taking Over

The Diagnostic and Statistical Manual of Mental Disorders (DSM) follows the medical illness model. This model assumes that symptoms reflect underlying disease entities; however, research following the DSM syndromes approach has not led to the discovery of underlying diseases. As such, DSM disorders are only a restatement of the symptoms that comprise them.

Although the DSM has failed to fulfil its ultimate purpose, Hofmann and Hayes report that it has still proved useful. It has led to 50 years of intervention research assessing which protocols are effective for specific disorders and has established numerous treatments as evidence-based. Yet, the protocol-driven approach has increased training requirements and disregarded the assessment of:

“What treatment, by whom, is most effective for this individual with that specific problem, under which set of circumstances, and how does it come about? – Gordon Paul (1969)

Hofmann and Hayes’ article goes on to detail a new generation of evidence-based care: process-based therapy. Process-based therapy takes us back to our roots—to conducting a functional analysis to understand the functional relationship between cues, context, and a person’s behaviour.

As indicated by its name, process-based therapy focuses on processes underlying psychopathology rather than on the content of that psychopathology. These next-generation therapies include, but are not limited to transdiagnostic therapy, dialectal behaviour therapy, mindfulness-based cognitive therapy, and functional analytic psychotherapy. These treatments place much less focus on protocols and more focus on evidence-based processes linked to evidence-based procedures.

Hofmann and Hayes make it clear that for these and other process-based therapies to succeed, they must show that they can (a) target a variety of processes that underlie psychological problems and (b) compete against alternative process-based models of care in terms of efficiency, effectiveness, training, and costs. Their theories will need to be scientifically supported and the treatment research will need to show us how changes occur, for whom they occur, and under what conditions.